GB1173443A - Semiconductor Device and Method of Fabrication thereof - Google Patents

Abstract

1,173,443. Semi-conductor devices. RADIO CORPORATION OF AMERICA. 25 May, 1967 [1 June, 1966], No. 24471/67. Heading H1K. A lead is connected to a semi-conductor device by positioning a semi-conductor pellet on a substrate, arranging a terminal structure so that a contact member of the structure engages the pellet, securing the terminal structure to the substrate so that the contact member is pressed against the pellet, bonding the contact member to the pellet, and disengaging the terminal structure from the substrate. A plurality of connected supports are formed from a strip of nickel-plated copper so that a plurality of semi-conductor devices can be assembled sequentially or simultaneously. As shown, Figs. 6 and 8, each support 12 is provided with a mounting area 16 surrounded by a dovetailed groove 18. A silicon transistor die 44 having a coating of lead on its lower surface and two bonding pads of lead on its upper surface, is positioned on the mounting area 16 and a nickel " clip " 28 is positioned transversely to the support. The clip 28 comprises two side sections 32 connecting end sections 30 from which extend resilient terminal members 36 having bent down end portions 40 which are pressed against the contact pads on the die 44. The side members 32 have recesses (34) which fit over the support 12 and the clip is secured in position by swaging tabs 20<SP>1</SP> on the support against the side members 32. The assembly is heated to solder the die to the support and the end portions of the terminal members to the contact pads. Encapsulation material is moulded over die 44 and terminal members 36 and enters the dovetail groove 18 which serves to anchor the encapsulation to the support. Each support is then separated from the original strip of supports, the swaged tabs 20<SP>1</SP> are removed to release the clip and each end section 30 is cut to leave a single strip extending from the encapsulation to form leads to the terminal members 36, Fig. 10 (not shown). In a modification the semi-conductor die is insulated from the substrate by a ceramic plate, for example of beryllia, and three terminal members are provided on the clip. In a second embodiment, Figs. 11 to 13 (not shown), a plurality of dice are positioned on connected supports and are contacted by terminal members extending from a strip which is secured to one edge of the support strip by deforming the sides of a slot in each support around tabs depending from the strip. The devices are then soldered and encapsulated and the strip is then subdivided to form leads for each terminal member and for the tabs secured to the substrates.